clinton Posted February 4, 2010 Share Posted February 4, 2010 I am working on getting a comonsence power hammer running it had no motor when I bought it, it was set up on a line shaft. Ok here is what I have the motor 1725 rpm 3'' pulley - the pulley on the hammer is 12'' this gives me 431.25 rpm I am going to step it down with a jack shaft using an 8'' step down to 5''= 269.53 rpm 3/1725 12/?=431.25 5/431.25 8/?=269.53 The info that I found on this hammer says hat it should run at 275rpm Is there anyone out there that can tell me if I am figuring this out right before I go out and buy the pulleys? Grant are you out there? I have been recalculating this and this is what I have now The motor=4.6''/1725 jackshaft=10''/793.5rpm other side of jack shaft= 4''/793.5 pulley on hammer 12''/264.5 rpm I am leaning toward the 4'' pulley on the jack shaft because I can buy it for a reasonable price from hit & miss (this is a flat belt drive pulley) Quote Link to comment Share on other sites More sharing options...
ArtWerkz Posted February 4, 2010 Share Posted February 4, 2010 Perhaps a speed reducer from your motor would be a quicker fix. Quote Link to comment Share on other sites More sharing options...
dkunkler Posted February 4, 2010 Share Posted February 4, 2010 It looks like all of your math is right for your speed reduction. Quote Link to comment Share on other sites More sharing options...
mike-hr Posted February 4, 2010 Share Posted February 4, 2010 I'm waiting for some paint to dry, so I went over your numbers, the second set looks good. The formula from Machinery's Handbook is Driving Diameter x RPM , then divide that by Driven Diameter. The actual speed of the hammer will most likely be a bit slower with slip factor. Ive made flat belt pulleys using black pipe for the diameter and plate steel for the ends, not too difficult if it will fit in the lathe. Quote Link to comment Share on other sites More sharing options...
clinton Posted February 5, 2010 Author Share Posted February 5, 2010 Ok thanks guys I will go for parts today they have to order the pulleys so I should be able to get this thing going next week and I will post some pictures Quote Link to comment Share on other sites More sharing options...
kasper Posted February 5, 2010 Share Posted February 5, 2010 Clinton are you running just a power hammer off the line shaft or do you have other tools on the line.In the near future i have plans to put line shaft in my shop as well,#50 canadian giant,power hack saw,and grinder.The best of luck.......regards Dave Quote Link to comment Share on other sites More sharing options...
Pat Roy Posted February 21, 2010 Share Posted February 21, 2010 I know this is coming late, but have you tried finding a 1200 rpm motor. That would save some belting and sheaves. A combination of 3" and 12" sheaves is a big reduction, but the biggest problem is there will be very little wrap on the small sheave and you might get slip and excessive wear. If you are going to use double reduction make them both a ratio of 2.5, but that's the engineer in me. Quote Link to comment Share on other sites More sharing options...
clinton Posted February 21, 2010 Author Share Posted February 21, 2010 Clinton are you running just a power hammer off the line shaft or do you have other tools on the line.In the near future i have plans to put line shaft in my shop as well,#50 canadian giant,power hack saw,and grinder.The best of luck.......regards Dave the hammer was originally on a line shaft I am putting an electric motor on this hammer, I found a flat drive pulley in my back yard of all places (duh) forgot that i had it it is 5 1/2 inches so I got the pulleys a 3'' on the motor to a 10'' on the jackshaft to the 5 1/2'' this should put me at 237 rpm I used two grove v belt sheaves. Got the motor mounted and the jackshaft installed so i ordered the flat belt from hit and miss and it should be here this week. The post that I mounted the motor to is attached to a threaded rod to allow for alignment and also lets me lay it over to my bench to get this behemoth of a motor mounted (heavy). here are a couple of pictures most of this stuff I had laying around I just had to buy the pulleys, shaft and pillow blocks Quote Link to comment Share on other sites More sharing options...
clinton Posted February 21, 2010 Author Share Posted February 21, 2010 I know this is coming late, but have you tried finding a 1200 rpm motor. That would save some belting and sheaves. A combination of 3" and 12" sheaves is a big reduction, but the biggest problem is there will be very little wrap on the small sheave and you might get slip and excessive wear. If you are going to use double reduction make them both a ratio of 2.5, but that's the engineer in me. I tried to find a lower rpm motor very pricey I got this one on ebay for around $175 with the shipping and it looked like they rolled it to my house the box was beat up bad when it got here Quote Link to comment Share on other sites More sharing options...
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